1. Field of the Invention
The invention relates to the development of a new yogurt product with significantly increased number of Lactobacillus acidophilus organisms along with usual number of Lactobacillus bulgaricus and Streptococcus thermophilus. The new yogurt also has dietetic fiber or food fiber, calcium carbonate, vitamins A, D, E, and C, along with high viable population of Lactobacillus acidophilus.
2. Description of the Prior Art
Yogurt is a fermented dairy product manufactured by fermenting milk with the aid of Lactobacillus bulgaricus and Streptococcus thermophilus. A brief dsecription of commercial yogurt manufacture is as follows:
1. Whole milk or partially skimmed milk fortified with nonfat dry milk (up to 3%) is pasteurized or heat treated and then cooled to 100.degree. to 110.degree. F.
2. The heat treated milk is inoculated with coccus (Streptococcus thermophilus), and rod (Lactobacillus bulgaricus) culture. Preferably, the coccus to rod ratio of the culture prior to inoculation is 1:1. Also, most generally the starter culture used is a frozen concentrate purchased from a commercial source. In some commercial preparation plants, a bulk starter medium is prepared by reconstituting nonfat dry milk solids in water, heating to 190.degree. F. for 1 h, cooling to 100.degree. to 110.degree. F., and inoculating coccus and rod frozen culture. The medium is incubated until pH drops to from 4.2 to 4.5 and then cooled to 40.degree. to 45.degree. F. This bulk culture is inoculated into yogurt mix at the rate of 1 to 2%.
3. The coccus and rod inoculated mix is incubated at 100.degree. to 113.degree. F. until pH drops from 6.6 to 6.0. At this stage, the yogurt mix is pumped into a dispenser and it is dispensed into a cup with fruit preserve at the bottom.
4. The cups are selaed and moved into a warm room (100.degree. to 114.degree. F.) and held until pH drops to 4.8. Then the cups are placed in a cooler until the yogurt is cooled to 40.degree. F. By then the pH of the final product is 4.0 to 4.4.
Whenever Swiss style type of yogurt is manufactured, the yogurt mix at pH 4.4 to 5.2 is mixed with the fruits and then it is filled into cups. Each manufacturer may have its own variations in making this yogurt.
Some of the manufacturers use Lactobacillus acidophilus or Lactobacillus bifidus along with the regular yogurt starter cultures, i.e. coccus (Streptococcus thermophilus) and rod (Lactobacillus bulgaricus). In this case, Lactobacillus acidophilus or L. bifidus is inoculated into the yogurt mix along with the regular yogurt cultures. The rate of growth of the yogurt cultures, coccus and rods, is much faster than that of L. acidophilus or L. bifidus. Consequently L. acidophilus or L. bifidus may not develop to a significant population. We have checked several commercial yogurts where L. acidophilus or L. bifidus initially was included and we could not detect significant number of L. acidophilus or bifidus bacteria. Even though the L. acidophilus or L. bifidus culture is added into yogurt mix, along with the regular yogurt cultures, the fate of the L. acidophilus is unknown. Perhaps L. acidophilus or bifidus cannot compete with the regular yogurt cultures. Consequently no one can make a deliberate statement with regard to acidophilus yogurt.
Literature documents the helpful, beneficial aspects of the L. acidophilus in the human being. They are:
1. Reduction of color cancer.
2. Reduction of intestinal flatulence.
3. Increased water retention in the gastrointestinal tract.
4. Reduction of cholesterol uptake into the blood stream.
5. Reduction of lactose intolerance.
6. Reduction of putrefactive and pathogenic bacterial population in the human gastrointestinal tract.
Thus far a successful way of including the L. acidophilus into human food has been in the form of "sweet acidophilus milk," where concentrated acidophilus bacterial culture is added to the cold fluid milk and then stored in the refrigerator. Such a milk most generally should have an L. acidophilus population of two million viable organisms per milliliter. Under acidic conditions (pH 3.0 to 4.0), L. acidophilus may not maintain its viability. Consequently, the latest fad is adding this organism to the fluid cold milk (pH 6.5 to 6.7).
It has been conclusively proven that a dietary fiber or food fiber included in the human diet has a pronounced effect on reducing colon cancer in human beings. In addition, it also has been claimed that fiber foods contribute to prevention of the following conditions: (1) constipation; (2) spastic colon; (3) intestinal diverticulosis; (4) varicose veins; and (5) excess cholesterol. Recently it also has been documented that high red meat consumption is increasing the incidence of colon cancer. This is because of the toxic end products formed in the gastrointestinal tract. Dietetic fiber increases the water retention in the gastrointestinal tract and thus reduces and dilutes the concentration of carcinogens in the intestinal tract. So far none of the dairy foods have significant amount of dietetic fiber included in them. Fruit base yogurts may have a slight amount of fiber if fresh fruits are included with skins. However most of the fruits are included with no skins and also in the form of puree.
Previous literature clearly states that L. acidophilus does not survive for a long period in yogurt. There also have been claims in literature regarding cancer retardation properties of vitamins A, E, and C. Further, vitamins C and E have an antioxidation effect, and consequently they may prolong the viability of the micro-organisms during storage.